Here I intend to gather things that I keep searching for over and over again in the internet since I can never remember what I did or how to do something when I need it. These “tips” wont necessarily solve your problems on your computer, it is only for my own convenience and as such I leave no guarantees that anything listed here will work or take any responsibility for any negative effects/outcomes you may encounter if you choose to try anything you find listed on this site.
Resetting the “System Management Controller” (SMC) on a MacBook Pro
I have a recurring issue at work where I hook my laptop up to a old external Apple LED Cinema Display. Earlier through a Thunderbolt1 port on my old computer and nowadays through an adapter to a Thunderbolt3 port. What we are “almost” talking about is a minidisplay port though since Apple is just always a bit special, it is not “exactly” the same thing.
Sometimes my laptop does not detect the external screens built in webcam, speakers, microphone or USB ports. If this happens, it is time to reset the SMC.
On the new computer, which is a 2017 year model, you power it down, making sure that the power adapter is attached and then press and hold down these keys (on the built in keyboard and not any external option).
control (⌃) + command (⌘) + space
Release these buttons at the same time and then proceed to boot your computer as usual with the power button. this has so far (at least) solved the described problem for me.
If you have a MBP model 2018 or newer (with the T2 chip) you should still power down while connected to a power source, hold and press the power button (on the built in keyboard and not any external option) for 10 seconds, then release and boot as usual.
In either case, you should not be alarmed if the initial boot sequence takes a while longer than usual.
Information gathered from Apple 2019-05-02 08:09